Y-Glutamyl derivatives

The interplay of kidney-selective transport and/or kidney-selective activation is well illustrated by the prodrug y-glutamyl sulfamethoxazole (6.24, R=H) and some A-acyl-y-glutamyl derivatives (6.24, R=acyl) [41], y-Glu-sulfamethoxazole, indeed, released sulfamethoxazole at high rates in kidney homogenates, whereas other organs showed low or negligible activity. Its... 

M. Orlowski, H. Mizoguchi, S. Wilk, W-Acyl-y-glutamyl Derivatives of Sulfamethoxazole as Models of Kidney-Selective Prodrugs , J. Pharmacol. Exp. Ther. 1980,212,167 -172. 

Orlowski, M., H. Mizoguchi, andS. Wilk. 197SN-Acyl-y-glutamyl derivatives of sulfamethoxazole as models of kidney-selective prodrugsl. Pharmacol. Exp. The212 167-172. 

Amino acid 78 and its y-glutamyl derivative are other components of the major pool of seleno compounds in accumulator plants, while selenomethionine (79) is the major compound in microorganisms like yeast, which is not specialized in selenium utilization. Se-Methylselenocysteine 5e-oxide (80), which is found in marine algae, tends to spontaneously decompose with the formation of pyruvate and ammonia via aminoacrylic acid and methaneselenic acid (81). The latter reacts with sulfhydryls or selenols to selenodisulfldes and diselenides. 

Block, E., Birringer, M., Jiang, W., Nakahodo, T., Thompson, H. J., et al. Allium chemistry synthesis, natural occurence, biological activity, and chemistry of Se-alk(en)ylselenocysteines and their y-glutamyl derivatives and oxidation products. J Agric Food Chem 2001, 49, 458 470. Das, A., Desai, D., Pittman, B., Amin, S., El-Bayoumy, K. Comparison of the chemopreventive efficacies of l,4-phenylenebis(methylene)selenocyanate and selenium-enriched yeast on 4-(methylnitrosamino)-l-(3-pyridyl)-l-butanone induced lung tumorigenesis in A/J mouse. Nutr Cancer 2003, 46, 179-185. 

Orihara, T. and Furuya, T. 1990. Production of theanine and other y-glutamyl derivatives by Camellia sinensis cultured cells. Plant Cell. Rep. 9 65-68. 

Glutathione, y-glutamyl derivatives, and (3-lyase substrates have been investigated as renal-specific prodrugs based on the presence of certain transporters such as plasma membrane transport systems for glutathione [28] and cysteine [29] conjugates and/or enzymes such as y-glutamyltrans-ferase (EC 2.3.2.2), dipeptidase, and p-lyase (EC4.4.1.13). 

During germination of kidney beans, in which 5-methylcysteine is present mainly in the form of the y-glutamyl derivative, there is a net loss of over 70% of the total -y-glutamyl-5-methylcysteine. Since no increase in acidic peptides equivalent to the net loss of y-glutamyl-5-methylcysteine could be detected, it was concluded that hydrolysis rather than transpeptidation had occurred, and it was suggested (Thompson et al., 1962) that y-... 

But a carrier can be fairly simple, as in the transport of amino acids from urine into proximal renal tubule cells. These convert the amino acid to its y-glutamyl derivative by the action ofglutamyltransferase and glutathione. Once inside the cell, the glutamyl group is excised and reconverted to glutathione (Meister and Tate, 1976). 

Contents B. FRASER-REID and R. C. ANDERSON, Carbohydrate Derivatives in the Asymmetric Synthesis of Natural Products — H. JONES and G. H. RASMUSSON, Recent Advances in the Biology and Chemistry of Vitamin D — S. LIAAEN-JENSEN, Stereochemistry of Naturally Occurring Carotenoids — T. KASAI and P. O. LARSEN, Chemistry and Biochemistry of y -Glutamyl Derivatives from Plants Including Mushrooms (Basidiomycetes) - Author Index - Subject Index. 

In addition to these ubiquitous amino acids, an additional 700 amino acids that are not involved in primary metabolism have been reported. About 300 of these are found in plants (Hunt, 1991). Most nonprotein amino acids occur free, as their 4-glutamyl (or y-glutamyl) derivatives, or linked to carbohydrate moieties. There are two main types of nonprotein amino acids. A number of nonprotein amino acids are similar to primary amino acids others are unrelated to any of these. Members of the first group may arise in three principal ways. Some nonprotein amino acids arise by simple structural modifications of protein amino acids others arise by modification of the pathways leading to protein amino acids a third group arises by novel routes. 

Chemistry and Biochemistry of y-Glutamyl Derivatives from Plants Including Mushrooms (Basidiomycetes)... 

IV. Chemical, Spectroscopic, and Analytical Properties of y-Glutamyl Derivatives 217... 

Degradation and General Chemical Properties of y-Glutamyl Derivatives. . 224... 

Occurrence of y-Glutamyl Derivatives in Different Parts of Plants and During... 

VIII. y-Glutamyl Derivatives with Toxic or Other Specific Biological Properties. .. 261... 

IX. Compounds Structurally Related to y-Glutamyl Derivatives from Plants. 263... 

A short review of y-glutamyl derivatives in plants has appeared in 1962 (330), and a general review of naturally occurring peptides published in 1966 (364) includes a list of 25 y-glutamyl peptides from plants. 

Some y-glutamyl derivatives have historically acquired trivial names. These names are indicated in Tables 2—6, and in most cases are used in the text. However, Tables 2—6 also give alternative systematic or semi-systematic names. 

The y-glutamyl derivatives of protein amino acids so far identified in plants are listed in Table 1. The table gives information on the character of the isolated material and attempts in this manner to give an indication of the reliability of the identification. In many cases no assignment of the configuration of the amino acids has been made but L-configurations are assumed. However, this cannot be taken for granted, especially... 

Table 1. y-Glutamyl Derivatives of Protein Amino Acids Identified in Plants... 

Compound Plant species Plant family Character of isolate, comments Configuration of Glutamic The acid second Ref. Chemical synthesis of y-glutamyl derivative... 

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